Push button switch



March 21, 1933. G. H. WHITTINGHAM 1,902,743

PUSH BUTTON SWITCH Filed Aug. 4, 1930 .5 l 4 f d of one will suffice for all.

f atented Mar. 21, 1 933 UNITED STATES PATENT arm:

GEORGE I-I, wnmtrmenmvr, or BALTIMORE, MARYLAND, ASSIGNOR- motion-Iron. con-1 'IEOLLER COMPANSL'OE BALTIMORE, MARYLAND, a couponrron, F MARYLAND PUSH BUTTON SWITCH Application filed August 4, 1930. Serial N 472,953.

. This invention relates to push button switches adapted for controlling the contactors of electriomotors, but suitable'also for other purposes. One object of the invention is to provide a push button switch of few parts which can be easily assembled and, which is readily. convertible from a normally closed switch to a' normally open switch, and vice versa. Another object of the invention is to provide a push button switch inwhich, the contact mechanism is arranged as a unit in a suitable casing, while the push button is arranged as a unit on the cover for the casing, so that by removing the cover the push button will beout of the way when it is desired to'have access to the contact mechanism, or the wiring within the casing.

The details of the invention will be clear from the accompanying drawing, in which:

Fig. 1 is a transverse section through aswitch casing and-switch, taken on the line 11 of Fig. 3;

Fig. 2 is a horizontal section on the line 22 of Fig. 1; and, s

Fig. 3 is a central longitudinal section throughthe casing showing a plurality of switches.

Referring to the drawing, 4; indicates a switch casing shown in the form of a sheet metal channel 1, having a removable top or cover plate 2. I The several push buttons 6, b, and b are shown mountedin the cover plate, and the switches 0, 0' and c which" these push buttons operate are mounted on a base 8 of insulating material in the bot tom of the casing. A thin sheet of insulating material 4 is laid on the bottom of the casing to prevent the metal parts connected with the switches from coming into contact with the bottom wall.

The switches are alike, and a description The switch 0 comprises a metal guide pin 5 which extends loosely through an opening in the longitudinal center of the base 3 and is provided with a head which rests upon the thin sheet of insulating material 4. Surrounding this J guide pin is a coiled spring 6, the ends of which rest in cups 7 and 8, which have censtationary contact members 11, both alike,

tral perforations, and which'a're antigen .the'guldepin. A metal contact disk 9,?

aving a central perforation, is slidable' on the rod and rests on the upper cup 8, and afdisk- 1 of insulating material, of larger diameter than the disk 9', has a central perforati n through which the guide pin'e'xtends, and V I this disk 10' rests on'the contact disk 9.

At opposite sidesof the guide pin are two and each comprising a flat foot piece 11 which is secured to the base 3 by a binding screw 12, a contact part 11 which projects upwardly at one side of the foot 'piece,-and an arm- 11 which projects upwardlyat the tends horizontallyj and fterminates in a These contact partsare spaced apart and the marginal portions of the disks opposite side of the 'footjjpiece, thenceexdownwardly inclined contact part 11, over i the part 11*. V

9 and 10 extend between the contact surfaces of both contact members.

In the switch 0', the spring presses the CllSkS jQ and 10 upwardly so that the insulating disk 10'rests against theupper contacts 11 and'theaswitch is normally open. To close'the switch,-"thedisks arepressed downwardly until the metal disk] 10 en gages the contactsll q Q 7 u If it is desiredto have a normally closed switch,-the, positionsof the disks 9 and-10 I are reversed. Thus, in thefsWitch'cfthe metal" disk 9*is uppermost and it is normally pressed against the upper contacts and the switch is normally closed. Downward pressure on the disks ofthis switch willopen" the screws 13, which secure theflbase 3 to'the casing, and raise the base a short distance, The guide pins 5 fit'loose'ly in the openings in the base and will not lift with 'thebase, or, if they do lift, they may" be pushed down farenough to permit of the 'r'emoval of the disks and .10. The disks are then'"reswitch from a normal- V jit, and continued downwardimovementwill cause the insulating disk 10 to engage the versed and replaced on the guide pin and the base is then secured to the casing by V the screws13. In the drawing, the switches c and c are shown as normally open switches and the switch a as a normally closed switch,

,The push buttons for operating the switches are separate units, mounted in the cover plate. In mounting the push buttons, a circular opening 14'is made in the cover so that it will be central over the switch 0, for instance, and a sheet metal thimble 15.,

having'an end flange 15 isinserted in the I thimblefiimmediatelyunder the plate.

opening, the flange resting upon the outer side of the cover plate. The thimble is then firmly secured to the cover plate by embossing a rib 15 in the peripheral wall of the p The thimble forms a housing for thespring 16. The push button 17 comprises a knob having a stem 17 a whichextends axially through the spring and through an opening in' the bottom of the thimble, and a sleeve 18, of I insulating material, is, secured to the lower end of the stem by a 'rivet 19. The sleeve forms a stop which abuts against the lower end of the thimble and limits the upward movement of the push button, and the sleeve terminates a short distance above the disks on the switch.

It will'be evident that depression or the push button 6 will force the insulating and metal disks downward, and when the metal disk bridges the contacts-11 the switch will be closed. When the push button is released, d

the spring will force the disks upwardly until the. insulating disk engages the upper contacts 11 Depression of the push button b will cause themetal disk '9 of the switch 0 to leave the upper contacts, there by opening the switch, and a further downward movement of the push button will cause the insulating disk 10 to abut against the lower contacts and limit the movement of the push button.

What I claim is:

1. A push-button switch comprising a base I of insulating material, a push-button springpressed away from the base,'a gulde-pln projecting from the base toward the pushbutton, stationary contact members arranged on the base at opposite sides of the pin, each member having two spaced contact surfaces, an insulating disk and a metal disk slidable onthe pin and both projecting between the spaced contact surfaces of both members, and a spring interposed between said disksa-ndthe base and normally pressing said disks toward the push-button.

2. A switch casing having a detachable cover, a base I of insulating material arranged withinthecasing, a switch mounted on said base and comprising a guide pin projectingtoward. the cover, stationary contact members at oppositesides of the pin,

each member having two spaced contact sea faces, an insulating disk and a metal disk slidable on the pin and both projecting between said spaced surfaces, a sprlng mterf posed between said disks and the base, and

jecting between said spaced surfaces and a spring interposed between said disks andthe base, and means for movlng sald disks comprising a thimble, concentric with the pin, 7

extending through an opening in the cover into the caslng and secured to the cover, a

push button movable in said thinible and having a shank extending through the bottom of the thimble, a sleeve of insulating material on the inner end of said shank adapted to ,bear against said disks, and a spring in said thiinble normally pressing said push button away from the disks.

In testimony whereof I affix my signature.

"GEORGE E. WHITTINGHAM. 

